Abstract

Developmental dysplasia of the hip (DDH) is characterized by insufficient acetabular coverage of the femoral head and is a recognized cause of hip pain, instability, and early osteoarthritis. Although bilateral deformity is common, symptoms often first develop in only one hip. The purposes of this study were: (1) to determine whether, in patients with bilateral DDH, side-to-side differences in three-dimensional (3D) femoral head coverage vary according to radiographic symmetry defined by the lateral center-edge angle (LCEA); and (2) to determine whether hips that appear radiographically symmetric still demonstrate focal 3D asymmetry.

This retrospective imaging-based study included patients with bilateral DDH who had pre-surgical radiographs and CT imaging suitable for 3D reconstruction. Subjects were stratified into radiographically symmetric (≤ 3° side-to-side LCEA difference) and asymmetric (> 3°) groups. 3D femoral head coverage was quantified for the whole head and for the anterolateral (AL), anteromedial (AM), posterolateral (PL), and posteromedial (PM) regions. Overall femoral head coverage did not differ significantly between LCEA symmetry groups. However, side-to-side differences depended on both regional location and radiographic symmetry group. Significant between-group differences were identified in AL, PL, and PM coverage, while AM and whole-head coverage were not significantly different. Within the radiographically symmetric group, a significant side-to-side difference was observed only in AL coverage. These findings indicate that bilateral DDH asymmetry is region specific and 3D in nature. Radiographic symmetry may still conceal focal structural asymmetry, particularly in AL region. 3D assessment may therefore provide information not captured by conventional two-dimensional radiographic measures.

Committee Chair

Michael D. Harris

Committee Members

Jin-Yu Shao, Patricia Widder

Degree

Master of Science (MS)

Author's Department

Biomedical Engineering

Author's School

McKelvey School of Engineering

Document Type

Thesis

Date of Award

Spring 5-2026

Language

English (en)

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Engineering Commons

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